The invention concerns a packaging machine with a horizontal-axis carousel, which falls within International Classification B65B11/28, particularly suitable for packaging rolls of paper, or stacks or packs of paper serviettes, or other solid products of variable size, the machine being equipped for this purpose with means to enable rapid and simplified adjustment of the dimensions of the seats of the carousel, to adapt them to the variable sizes of the products to be packaged.
It should be noted that in the definition of the seat of the carousel, the term ‘longitudinal walls’ will be use to referred to the walls opposite to each other and parallel to the axis of the carousel, designed to support the product laterally and the distance between which varies with the diameter or height of the product, while the term ‘transverse walls’ will be use to referred to those perpendicular to the axis of the carousel, usually positioned between said longitudinal walls, designed to cooperate with the ends of the product and the distance between which varies with the length of the product.
Patent EP 165.204 is cited as known state of the art. This patent describes a carousel provided with seats with one of the longitudinal walls fixed and the other oscillating on an axis parallel to that of the carousel and therefore easily adaptable to products of variable width, and provided with opposite transverse walls, of which the certain ones, are supported by a secondary carousel internally facing the main one and mounted on a shaft coaxial with and inside that of the main carousel and which can be made to slide axially upon command, while the outer transverse walls are supported by telescopic arms that longitudinally carry a pinion mechanism with two opposed racks. One of these racks is integral at the end of said telescopic arm with the outer transverse wall, while the other rack is connected to said secondary carousel. To reduce the distance between said two transverse walls of the seats, it is necessary to axially move the secondary carousel away from the main one for the inner transverse wall to approach the outer one, which is automatically moved towards the inner transverse wall by said rack and pinion mechanism, with an equal and self-centring displacement. In this solution, the machine's zero reference is constituted by the transverse centre-line plane of the seats of the carousel, with respect to which the centre line of the reel from which the packaging material is unwound must be kept longitudinally aligned, and so the support means of the reel must also be equipped with systems for the self-centring positioning of the reel.
Packaging machines are also known of the type described, for example, in British Patent GB 527 982, in which the transverse walls of the seats that are internal and close to the carousel are kept fixed, while as the length of the product to be packaged varies, the distance between said inner transverse walls and the outside ones is varied, the latter being associated with common support means for this purpose, for example a secondary carousel, such that by modifying its axial distance from the main carousel that supports the longitudinal walls and the fixed, inner transverse ones of the seats, it is possible to adapt the internal dimensions of the seats to the changes in length of the products to be packaged. In this last case, the machine's zero reference is constituted by said inner transverse walls of the seats, with respect to which the side of the reel of packaging material facing the main carousel is kept fixed.
The publications of patent applications JP 2003/128005 A and EP 0 888 968 A are also cited as known state of the art.
All of the known solutions considered above have strengths and weaknesses, but all have drawbacks of limited accessibility to the seats from the inside and from the other side of the main carousel, are constructively complex and do not have seats than can be adjusted in a simple, rapid, precise and centralized manner, nor modular characteristics that, as well as rendering production of the machine more economic, allow them to be easily set up for clockwise or anticlockwise rotation of the carousel, with product unloading to the right or to the left of the carousel, according to the user's lay-out requirements.